Electric lamp.



V F, G. KEYES.

ELECTRIC LAMP. APPLICATION min FEB. 11. 1914.

Patented Jan. 28', 1919.

WIT/M8858 a citizen of the United States, and

' is suddenly with the lower ends of lea ELECTRIC COMPANY FB.EDEBICK G. KEYES, OF EAST ORANGE, NEW JERSEY, ASSIGNOB TO COOPER HEWITT OF HOBOKEN, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELECTRIC LAMP.

Specification of Letters Patent.

Patented J an. 28, 1919.

Application filed February 11, 1914. Serial No. 818,005.

To all whom-it may concern:

Be it known that I, FREDERICK G. KEYES, resident v f Essex, State of invented certain new and Electric Lamps, of following is a specification.

found in practice that the presence of a trace of moisture in metal ament lamps increases very materially the rate at which the discharge of particles from the filament and the consequent blackening or darkening of the light transmitting envelop takes place.

The water vapor is 1 e fused over the hot filament of East Orange, New Jersey, have useful Improvements in which the It has been an is there practically completely dissociated, the oxygen unitin with the filament material. n the case 0 tungsten, the oxid is liquid at the temperature at which the filaments are operated. Under these conditions the oxid transformed into vapor and deposits upon the cooler lass surfaces. Oxyen in its free state wil of course, unite directly with the tungsten orother metallic material, producing the same result. Consequently it is advisable to introduce into the lamp a substance which will eifectively absorb minute traces of water vapor an oxygen. As a suitable material for pose, I propose calcium or other alkaline earth metals, or alkali metals, usually in the form of turnings or powder. The heat disengaged while the lamp is in operation increases the' chemical activity of the alkaline earth metal and increases the rate at which water vapor and oxygenwill be absorbed.

My invention is illustrated in the accompanying drawings in which Figure 1 is a vertical section through the major portion of a tungsten lamp, the lower part of the globe being shown without section lines, and Fig. 2 is a plan of a tungsten filament wel suited for use in connection with lamps 0 this character; and Fig. 3 is a detail view of a modification. In the drawings 1 is the outer globe of a. tungsten lamp and 2 a tubular extension thereof having a reentrant port1on, 3, within which the sealing of the lamp is accomplished.

The tungsten filament is shown at 4 and is provided with terminal pieces, 5, 5, which are connected in any suitable manner (herein shown as a screw thread connection) ds, 6, 6. The filaprovided.

this puras a spiral, and at several the spiral is spread out, as prevent the contact mg of adjacent coils of the spiral at points where the filament sags naturally by reason of the weight of the filament or for any other reason. Anchor wires, 8, 8, are shown tipped with tungsten wire, 9, 9. This wire is bent around the spread out portions of the filament whereby adequate support is shown at wires 8, 8 are shown as passing up through a diaphragm, 10, of aluminum or some other suitable metal, the said parts where they pass through the diaphragm being surrounded by sleeves, 11, 11, of quartz and being covered at the top of the diaphragm with masses, 12, 12, of paste or cement formed of some vitreous adhesive material whereby, in the case of the lead 6, 6 the leads themselves are held from twisting as will be readily understood. At the top of the wires 6, 6 sockets, 13, 13, are sealed on. These may be of any conven'ent depth, and they are adapted to receive the lower ends of copper leads. 14. 14, which pass through sleeves 16. 16, of platinum; and the parts are all secured together by iron caps, 17 17, which are welded to the platinum tubes and to the tops of the leads 14, 14.

In the present instance the metallic diaphragm 10 is supported in a manner presently to be described. The object of the diaphragm is to prevent the entrance of unnecessary or undue heat into the tubular extension 2 where the sealing of the lamp takes lace.

To the bottom of the re'ntrant portion is secured or made integral a solid glass. 18. to the lower end of which is secured a glass tube, 19, which is itself secured at the bottom to another solid glass piece, 20, having a shoulder, 21 and a lower portion which passes through the metal phragm 10. After being passed through the diaphragm this soli lower end is formed into a second shoulder, 22, lying underneath the diaphragm 10, so that the latter is held firmly by the glass portion and its shoulders 21 and Near the top Of\ the tubular portion 19 are formed. holes or openings, 23, and one of the first operations is to invert the tube and place inside it a small piece, 24, of glass wool. Calcium or some alkali or alkaline The leads 6, 6 and the anchor piece of diawithin-the t ereupon v secured to t r to com'pletethe struc is th be coiled he alkaline ear case V may be, serve the globe 1. a

be understood that the particular to the tube 19, within the a S ls for th ssen'tial feature of parts numbered ,in the i ilnurious g as 18,19 and It locat' extension 2, is the invention. other figures of 20 are he tubular disk 10 to higher active. v I claim as my 1. In a tungste filament of tu filament, a globe with the lamp piece of glass, with the bottom said tion, the said ab mote from the lamp fila of powder or turnatthe bottom of the rating two passing out glass wool s then glass woolne earth is held part, 20,

but is prevente the openings 1e 'mouth of the by. another ali ,or alkali posed in compact for strain upon the pressing upon he copper lead able support forthe of the lead Wires.

4 In an incandescen p11 ragm, terminal lead the same and a su independent of the lead 11 an incandescent m, terminal lead wires passin a support for dependent of thele d Wires,

pass through the d connected to special flexib n at 26, 26.

th metal or al kali, as the s to absorb th e excess of re shown as of 1n :1 reentr are mounted, a

.ture. Thereafter 3.

ake up the o.

v phrag deposition of the same,

New York d State of N nary, A. D. 1914.

FREDERICK G. KEYES.

I 2. In a tun of the glass pie tubular exte phragm sub extension f1 with lead w whlch In an incand m'ent.

Signed at New York an day of Febr por- Witnesses material being re- WM. H.. CAPEL,. THOS. H. BROWN.

gsten lamp, a dia portions of the 1 piece of glass, centrally tubular, from one end of th supporting the said shoulders ab phragm' sepaamp globe, a

e inclosing diaphragm b ove and below the shoulders being formed on a soli ce, and the diap end in ing remote from the lampfilam In a tungsten lamp, a suitable filament of tungsten within nsion of the stantially closi y means of said globe, a obe and a dia-' ng ofithe tubular e, in combination aments and a suithragm independent om the glo ires for the fil diap wires pport for electric lamp, a diaphragm 1nthe lead wires laphragm being pper leads, said copper l escent ele gases are de eration, a globecontainin ed to be brou extension ctric lamp where ed during opg a filament adaptdescence, a tubular a diaphragm subextension from the gh't to mean of said globe, stantiall-y closing ofi' the Increasingly globe so as to prevent in the county of York this 10th 90 

